I had five jw's study with me back during 1968-1969 on short term studies. This was the exciting time period for the 1975 fiasco. Well not one of those five jw's mentioned anything about marking, shunning or disfellowshipping policies.
I worked with a young man who was df'd by an elder who worked for the same employer and was shunned. This happened during the early 1970's. This shunning policy started up big time around 1980 and is on the increase.
If I knew back during the 1960's what I know now, I would not have had anything do with baptism.